Check out the Cadillac produced reveal of the all-new Cadillac ATS.

Poke around under the all-new 2013 Cadillac ATS luxury sports sedan and you're bound to find a few holes. That's a good thing.

"We had a mantra: 'Every gram, by every engineer, every day,'" said chief engineer David Masch, who led the General Motors team that developed Cadillac's BMW 3-series fighter unveiled on Sunday for the Detroit auto show. "We approached development by counting all the grams in the ATS. We minimized them where we could and put them to the best use where they were needed."

Masch's team spent five years building the rear-drive ATS from the ground up, including two years benchmarking the 3-series, the Audi A4, the Mercedes-Benz C-class and the Lexus IS. Their research confirmed, in part, what they already knew: The Cadillac CTS is a competitive sports sedan in its own right but the car is too large compared with its trimmer competitors in the global marketplace. Thousands of weight-saving decisions later, the resulting ATS checks in at less than 3,400 pounds, about 500 pounds lighter and eight inches shorter overall than the CTS.

"In this segment, performance is the No. 1 attribute that people are looking for," Masch said. "It's all about ride and handling and making the car fun to drive."

Besides weight savings, performance was paramount in decisions such as installing undercarriage panels to manage airflow, trunk-mounting the battery to help reach a 50/50 weight distribution and locating the variable-effort steering gear forward of the wheels for optimum steering feel and response in aggressive driving maneuvers. Engineers track-tested six different suspensions before settling on Cadillac's first five-link independent rear setup, said Robert Kotarak, vehicle-performance manager.

Power comes from a choice of engines: a 318-hp, 267-lb-ft, 3.6-liter V6 and two four-cylinders, one a turbocharged 270-hp, 260-lb-ft 2.0-liter and the other a naturally aspirated 200-hp, 188-lb-ft 2.5-liter. Manual and automatic six-speed transmissions are offered, and all-wheel drive is optional. The car goes on sale this summer.

Mark Reuss, president of GM North America, said a diesel engine will also be offered during the ATS's first product cycle.